The Stock Glitch is a glitch in Melee that allows you to play a character with the stock design of another character. This will also show the character of the stock design you're using underneath the character roster. Also, the token will be on the character you're actually using to fight when you do this Glitch. If you press Y or X after you've done the glitch correctly, the bottom of the screen will show the actual character and the Stock Glitch won't work. This has been discovered in 2009 by EPsilon933.
People will sometimes do this in tournaments or in friendlies. The most common stock designs out of this Glitch are Yoshi's and Kirby's stock design.
How to do the Stock Glitch
1. Select a character
2. Hit the B button once
3. Place your icon over another character
4. Do not press the A button
5. Hit the Y button once
6. Press L + R + Start
7. Go back to VS. Mode and Melee
8. Press Start
If done correctly, the glitch should occur.